The present invention relates to systems and methods for embossing a surface of an embossable fabric with a stream of air, and embossed flocked fabrics made thereby.
In manufacturing flocked fabric it is conventional to deposit a layer of flock on an adhesive coated substrate and to emboss the surface of the flocked fabric during this process with selected designs. Conventionally, the embossing process may be achieved by one of several processes using specialized equipment for such purposes. Among these embossing processes is air embossing. In the air embossing process a substrate is coated with an adhesive. While the adhesive is still wet it is covered with a layer of flock fibers forming the flocked layer. The adhesive coated substrate with the flocked fibers is then carried beneath a stencil while the adhesive is not yet set. The stencil under which the assembly moves typically comprises an elongated cylinder having perforations arranged in a desired pattern to be formed in the flocked surface. This embossing stencil typically is rotated at the same speed as the flocked layer moves beneath it. Air introduced within this cylindrical stencil is directed downwardly through the perforations forming the pattern onto the upper surface of the flocked layer. By choosing a particular arrangement of perforations in the screen, and by the selective application of air flow through the perforations, air jets are projected downwardly from the stencil onto the surface of the flocked fabric. Since the flocked fabric has not yet set in the adhesive, the stream of air changes the angle of or substantially flattens the flock fibers forming the flock in selected areas, thus forming a pattern as the stencil rotates and the flocked fabric moves.
A variety of prior art systems are available for performing air embossing of flocked fabrics. Many such systems are generally satisfactory for embossing designs onto an embossable surface of the fabric that do not require a significant level of fine detail. However, typical prior art systems suffer from a variety of shortcoming which limit their utility for producing finely detailed patterns, and which result in embossed pile fabrics that include embossed regions having undesirable artifacts and visually unappealing surface features. For example, air embossed pile fabrics produced with conventional air embossing equipment are typically not able to produce embossed features having a characteristic size that is very small, thus such equipment is not able to give the embossed fabric an appearance with a fine, detailed surface structure. In addition, typical prior art air embossing systems are not able to direct air towards the embossable surface of the fabric at a controlled, desirable angle (e.g. essentially perpendicular to the fabric surface), and, thus, they tend to produce embossed features having a blurred or imprecise transition region between the embossed features and the unembossed regions of the surface, which results in an associated lack of crispness and definition to the overall appearance of the embossed fabric.
In addition, typical prior art air embossing systems also tend to produce embossed fabrics having embossed features distributed across the width of the fabric that are not uniform in appearance across the width of the fabric. Also, typical prior art air embossing systems have a tendency to direct air towards the surface of the fabric in a direction diagonal to the fabric surface resulting in an embossed surface wherein the pile fibers have an overall directional lay with respect to the substrate, thus creating a distorted, unattractive appearance in the embossed surface, which appearance does not accurately reflect the pattern provided in the stencil used for embossing.
The present invention is directed to improved air embossing systems and methods and improved embossed fabrics produced using the systems and methods. The invention provides a variety of air embossing systems utilizing improved air lances for directing air onto and through a patterned stencil of the system. The improved air lances and embossing systems provided by the invention are able, in many embodiments, to solve many of the above-mentioned short comings of prior art air embossing systems and to produce embossed fabrics having an unprecedented level of fine detail, crisp transition between unembossed and embossed regions, and uniformity across the width of the embossed fabric.
The present invention provides, in some embodiments, improved air embossing systems, improved air lances, and improved methods of air embossing fabrics, which are able to produce an unprecedented level of fine detail, crisp transition between unembossed and embossed regions, and a high degree of uniformity across the width of an embossed fabric, when compared to the performance of typical, conventional air embossing systems, air lances, and embossing methods. The air embossing systems provided by the invention, in some embodiments, utilize air lances for directing a stream of air onto the embossable surface of a fabric that have at least one nozzle having a characteristic orifice dimension substantially less than that of conventional air lance nozzles. The disclosed air embossing systems can also include air lances having nozzles positioned in close proximity to the embossable surface of a fabric being embossed, substantially closer than is typical for air lances employed in conventional air embossing systems. Air lances provided according to the invention can also include one or more nozzles having a characteristic orifice dimension that is substantially less than a characteristic length of the nozzles. Certain air lances provided according to the invention can also include one or more nozzles in the shape of an elongated slit oriented, with respect to the air lance, so as to be positioned across essentially the entire width of a fabric being embossed with the air lance. The invention also provides air lances for use in embossing fabrics that can include a nozzle-forming component that is separable from the main body of the air lance and that enables the nozzle(s) of the air lance to be positioned within close proximity to the fabric, when the air lance is in operation, and that also can act to redirect air flowing within the air lance such that it is emitted from the nozzle(s) so that a substantial fraction of the air stream is directed essentially perpendicular to the surface of the fabric being embossed. Yet other air lances disclosed include therein one or more baffles or air redirecting elements, which serve to deflect air flowing within the air lance so that it passes through the nozzle(s) and is directed onto the embossable surface of the fabric at an angle that is substantially greater, with respect to the longitudinal axis of the air lance, than the angle of an air stream emitted from a nozzle of an essentially equivalent air lance, except excluding the air redirecting element or baffle. Some of the air lances described according to the invention can include a combination of several or all of the above described features.
In one embodiment, a system for air embossing a surface of an embossable fabric is disclosed. The system comprises a stencil having a first surface and a second, fabric-facing surface that is positionable adjacent and in spaced proximity to the embossable surface of the fabric during air embossing. The system further comprises an air lance comprising a main body portion and including at least one nozzle. The nozzle is constructed and positioned to direct a stream of air through at least one opening in the stencil and onto the embossable surface. The air lance is secured within the system to maintain the nozzle in a fixed, predetermined position relative to the first surface of the stencil during operation. The air lance is positioned such that the nozzle is positioned so that at least a portion thereof, which is closest to the stencil, is separated from the first surface of the stencil by a first distance, when the system is in operation. The air lance is also positioned such that the smallest distance separating the main body portion of the air lance from the first surface of the stencil exceeds the first distance.
In another embodiment, a system for air embossing a surface of an embossable fabric is disclosed. The system comprises a stencil and an air lance including at least one nozzle thereon. The nozzle is constructed and positioned to direct a flow of air through the stencil and onto the embossable surface of the fabric, when the system is in operation. The system further comprises a substantially smooth support surface comprising a cylindrical roller constructed and arranged to support the underside of the fabric during air embossing of the embossable surface of the fabric with the system. The cylindrical roller is positioned directly beneath and spaced apart from the nozzle such that a stream of air exiting the nozzle is directed to impinge upon the fabric at a location where the fabric is adjacent to and in contact with the cylindrical roller, when the system is in operation.
In another aspect, an air lance for directing air through a stencil and onto a surface of an embossable fabric for air embossing the fabric is disclosed. The air lance comprises a conduit having at least one opening therein and at least one orifice forming at least one nozzle. The nozzle is constructed and positioned to direct a stream of air through the stencil and onto the embossable surface of the fabric when the air lance is in operation. The nozzle has a characteristic orifice dimension not exceeding about 0.05 inch.
In another embodiment, an air lance for directing air through a stencil and onto a surface of an embossable fabric for air embossing the fabric is disclosed. The air lance comprises a conduit having at least one inlet opening therein and at least one orifice forming at least one nozzle. The nozzle is constructed and positioned to direct a stream of air through the stencil and onto the embossable surface of the fabric when the air lance is in operation. The nozzle has a characteristic orifice dimension not exceeding a maximum characteristic length of the nozzle.
In yet another embodiment, an air lance for directing air through a stencil and onto a surface of an embossable fabric for air embossing the fabric is disclosed. The air lance comprises a conduit having an elongated main body portion with at least one inlet opening and at least one outlet opening therein. The air lance further includes a nozzle-forming component connected to the main body portion and extending along a substantial fraction of the length of the main body portion. The nozzle-forming component includes at least one orifice therein forming a nozzle. The nozzle is in fluid communication with the outlet opening of the main body portion and is constructed and positioned to direct a stream of air through at least one opening in the stencil and onto the embossable surface of the fabric when the air lance is in operation. The nozzle-forming component is shaped and positioned so that the nozzle in the nozzle-forming component is separated from a first surface of the stencil onto which air is impinged by a distance that is substantially less than a distance separating the first surface of the stencil and the outlet opening in the main body portion of the conduit.
In yet another embodiment, an air lance for directing air through a stencil and onto a surface of an embossable fabric for air embossing the fabric is disclosed. The air lance comprises an elongated tubular conduit having at least one inlet opening therein and at least one internal support strut attached therein. The support strut is constructed and positioned within the conduit to resist expansion of the conduit when the air lance is in operation. The air lance includes at least one orifice in the shape of an elongated slit forming at least one nozzle. The nozzle is constructed and positioned to direct a stream of air through at least one opening in the stencil and onto the embossable surface of the fabric, when the air lance is in operation.
In another embodiment, an air lance for directing air through a stencil onto a surface of an embossable fabric for air embossing the fabric is disclosed. The air lance comprises a conduit having at least one opening therein and at least one orifice forming at least one nozzle. The nozzle is constructed and positioned to direct a stream of air through at least one opening in the stencil and onto the embossable surface of the fabric when the air lance is in operation. The air lance further comprises at least one air redirecting element constructed and positioned with respect to the nozzle so that the fractional amount of the stream of air directed through the opening in the stencil essentially perpendicular to the embossable surface of the fabric is increased with respect to a fractional amount of a stream of air directed through the opening in the stencil essentially perpendicular to the embossable surface of the fabric by an essentially equivalent air lance, except not including the air redirecting element.
In another aspect, a method for air embossing a surface of an embossable fabric is disclosed. The method comprises supplying a flow of air to an air lance and flowing a stream of air through at least one nozzle of the air lance so that essentially the entire stream of air is directed towards a surface of a stencil facing and adjacent the nozzle at an angle of at least about 45 degrees with respect to a longitudinal axis of the air lance. The method further comprises passing the stream of air through at least one opening in the stencil and impinging the stream of air onto the embossable surface of the fabric, thereby embossing the embossable surface of the fabric.
In another embodiment, a method for air embossing a surface of an embossable fabric is disclosed. The method comprises supplying a flow of air to an elongated air lance including one or more nozzles positioned along a substantial fraction of the length of the air lance. The method further comprises flowing a stream of air through the one or more nozzles such that the air velocity through the one or more nozzles is essentially constant along the substantial fraction of the length of the air lance. The method further includes passing the stream of air through at least one opening in the stencil and impinging the stream of air onto the embossable surface of the fabric, thereby embossing the embossable surface of the fabric.
In yet another embodiment, a method for embossing a surface of an embossable fabric is disclosed. The method comprises supplying a flow of air to an air lance, flowing a stream of air through at least one nozzle of the air lance so that the velocity of the air exiting the nozzle is at least about 12,000 ft/min, passing the stream of air through at least one opening in the stencil, impinging the stream of air onto the embossable surface of the fabric, and embossing the embossable surface of the fabric with a predetermined pattern of embossed features.
In another embodiment, a method for air embossing a surface of an embossable fabric is disclosed. The method comprises supplying a flow of air to an air lance, flowing a stream of air through at least one nozzle of the air lance, rotating a cylindrical stencil disposed around at least a portion of the air lance at a first speed, passing the stream of air through at least one opening in the rotating stencil, moving the fabric adjacent to an outer surface of the stencil at a second speed that is different from the first speed of the rotating stencil, impinging the stream of air onto the embossable surface of the fabric, and embossing the embossable surface of the fabric with a predetermined pattern of embossed features.
In another embodiment, a method for air embossing a surface of an embossable fabric is disclosed. The method comprises positioning at least a portion of at least one nozzle of an air lance within a first separation distance from a first surface of a stencil, positioning a main body portion of the air lance so that the smallest distance separating the main body portion from the first surface of the stencil exceeds any distance separating the nozzle from the first surface of the stencil, forming a stream of air with the air lance by passing air through the nozzle of the air lance, and directing the stream of air through at least one opening in the stencil and onto the embossable surface of the fabric to form a predetermined pattern of embossed features.
In yet another embodiment, a method for air embossing a surface of an embossable fabric is disclosed. The method comprises positioning a substantially smooth support surface comprising a cylindrical roller directly beneath and spaced apart from the nozzle of the air lance. The method further comprises supporting the underside of the embossable fabric with the cylindrical roller and directing a stream of air with the nozzle through a stencil and onto the embossable surface of the fabric such that the stream of air impinges upon the fabric at a location where the fabric is adjacent to and in contact with the cylindrical roller.
In yet another embodiment, a method for air embossing a surface of an embossable fabric is disclosed. The method comprises directing a stream of air though a stencil and onto the embossable surface of the fabric with an air lance including a conduit, having at least one inlet opening therein, and at least one orifice forming at least one nozzle having a characteristic orifice dimension not exceeding about 0.05 inch.
In another embodiment, a method for air embossing a surface of an embossable fabric is disclosed. The method comprises directing a stream of air through a stencil and onto the embossable surface of the fabric with an air lance including a conduit, having at least one inlet opening therein, and at least one orifice forming at least one nozzle having a characteristic orifice dimension not exceeding a maximum characteristic length of the nozzle.
In yet another embodiment, a method for air embossing a surface of an embossable fabric is disclosed. The method comprises directing a stream of air through a stencil an onto the embossable surface of the fabric with an air lance including a conduit, and a nozzle forming component including at least one orifice therein forming a nozzle that is in fluid communication with the outlet opening in the main body portion. The nozzle forming component is shaped and positioned to extend along a substantial fraction of the length of the main body portion and so that the nozzle in the nozzle forming component is separated from a first surface of the stencil, onto which the stream of air is impinged, by a distance that is substantially less than a distance separating the first surface of the stencil and the outlet opening in the main body portion of the conduit.
In another aspect, in a system for air embossing an embossable fabric, means are disclosed for directing a stream of air onto the embossable surface of the fabric from a distance of no more than about 0.75 inch, with at least one cross-sectional dimension of the air stream being no more than about 0.2 inch at its source.
In yet another aspect, an air embossing system for embossing a surface of an embossable fabric is disclosed. The air embossing system comprises an elongated conduit extending across and substantially parallel to the embossable fabric and further includes means for redirecting air flowing along the length of the conduit so that essentially all of the air flow exits from at least one outlet opening in the conduit towards the fabric in a direction making an angle of at least about 45 degrees with respect to the longitudinal axis of the elongated conduit, with the means comprising a series of baffles shaped and positioned to intercept and deflect the air flow.
In another embodiment, a method for embossing a surface of an embossable fabric is disclosed. The method comprises directing a stream of air through a stencil and onto the embossable surface of the fabric with an air lance including an elongated tubular conduit. The conduit has at least one inlet opening therein, at least one internal support strut attached therein, which support strut is constructed and positioned within the conduit to resist expansion of the conduit when the air lance is in operation, and at least one orifice in the shape of an elongated slit forming at least one nozzle.
In yet another embodiment, a method for air embossing a surface of an embossable fabric is disclosed. The method comprises directing a stream of air through a stencil and onto the embossable surface of the fabric with an air lance including a conduit, the air lance having at least one inlet opening therein, at least one orifice forming at least one nozzle, and at least one air redirecting element constructed and positioned with respect to the nozzle so that the fractional amount of the stream of air directed through the stencil essentially perpendicular to the embossable surface of the fabric is increased with respect to a fractional amount of a stream of air directed through the stencil essentially perpendicular to the embossable surface of the fabric by an essentially equivalent air lance, except not including the air redirecting element.
Other advantages, novel features, and objects of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings, which are schematic and which are not intended to be drawn to scale. In figures, each identical, nearly identical, or closely similar component that is illustrated in various figures is represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention.